1. Field of the Invention
The invention relates to an emptying station for bulk bags, in particular for bulk bags containing particulate hazardous materials, such as cyanuric chloride. The emptying station of this invention is especially useful for emptying bulk bags in a dust-free, safe manner and for rinsing the emptied bags.
2. Description of the Related Art
Various devices are known for emptying bulk bags, which as referred to herein mean large packaging containers which have in particular a capacity of from 100 to 1000 kg and are made of single-ply or multi-ply sacking material. U.S. Pat. No. 5,944,070 discusses one such device, which is purportedly useful for preventing problems arising during emptying of a bulk bag comprising an inner sack and an outer sack. The emptying device comprises a double-tube structure having an inner tube and an outer tube, a holding device arranged centrally above the inner tube for receiving a bulk bag, a raisable and lowerable closing ring for closing the upper end of an annular gap formed by the inner and outer tubes of the double-tube structure, and gripping and pulling devices for gripping and pulling taut the discharge neck of the inner sack. In operation, a bulk bag is inverted and lowered so that its outlet neck is gripped and pulled into the inner tube. The tie of the discharge neck can then be untied to release the contents of the bulk bag into the inner tube. Although this device allows safe emptying of powder-form bulk material, such as cyanuric chloride, handling of bulk materials with this device is rather complex. Another drawback of the device disclosed in U.S. Pat. No. 5,944,070 is that no provision is made for rinsing the emptied bulk bag before disposal of the emptied bulk bag.
It is also known in the art to cut open the bottom of a bulk bag suspended from a carrier means by lowering the bulk bag onto an opening device to thereby empty the bulk bag. The opening device consists of commercially available cutters known as pyramid cutters. At least three cutters are used in the opening device, and in the case of bulk bags of substantially rectangular cross section, preferably four cutters are used. The cutters are arranged in a pyramid with their blades coming together at the top to form an apex of the pyramid. A pin is positioned at the pyramid apex for piercing the bottom of a bulk bag lowered onto the opening device. The pyramid cutters are conventionally arranged in a bulk bag receiving means provided with an outlet. During the opening operation, the bulk bag is lowered through a top opening of the bulk bag receiving means until the bulk bag is pierced then cut by the pin and cutters, respectively. During the emptying operation, a stationary rubber sleeve arranged between the bulk bag and the receiving means functions to reduce the amount of dust escaping through the top opening. The rubber sleeve is constructed as an inverted bowl or as a cylindrical element. However, the rubber sleeve is only partially effective, making devices equipped with the rubber sleeve unsatisfactory for emptying bulk bags filled with hazardous materials. Such emptying stations also lack means for rinsing out the bulk bag with a liquid rinsing agent immediately after emptying thereof. The absence of an effective rinsing means allows contents of the bulk bag to remain adhered to the sack wall after the emptying operation is complete, since no rinsing means is provided for dissolving or rinsing the residual contents away.